JP2708108B2 - 3D image display device - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a binocular stereoscopic image display device using polarized glasses.

[Conventional technology]

Equipped with two sets of video light sources that derive two sets of video light that can be viewed on top of each other, such as video light captured by two cameras with different viewing angles, and a set of video synthesis surfaces A two-lens stereoscopic image display device capable of viewing a stereoscopic image by combining two sets of image light through polarized glasses having different polarization directions on the left and right has been put to practical use.

As described in Japanese Patent Application Laid-Open No. 63-316037, this type of conventional apparatus can be broadly classified into a projector system and a cathode ray tube system. The projector system uses a screen as a video synthesis surface, and the cathode ray tube system uses a video synthesis surface. Is a half mirror.

These stereoscopic image display devices, by attaching a polarizing filter having a different polarization direction to each image light source,
The polarization directions of the two sets of image light transmitted to the image synthesis surface are made different. That is, a horizontal / vertical linear polarization system in which a horizontal linear polarization filter is attached to one image light source and a vertical linear polarization filter is attached to the other image light source,
Alternatively, a + 45 ° linear polarization filter and -45 ° for each image light source
+ 45 ° / -45 ° with linear polarizing filters respectively
The polarization directions of the two sets of image light are made different from each other by a linear polarization method or a counterclockwise / clockwise circular polarization method in which a left-handed circular polarization filter and a right-handed polarization filter are attached to each image light source.

In order to view the synthesized image as a stereoscopic image, wear polarizing glasses provided with left and right polarizing filters corresponding to each polarization direction. For example, in the horizontal / vertical linear polarization method, when a horizontal linear polarization filter is attached to an image light source that transmits an image of a left camera, and a vertical linear polarization filter is attached to an image light source that transmits an image of a right camera. A horizontal linear polarizing filter is used on the left eye side of the polarizing glasses, and a vertical linear polarizing filter is used on the right eye side.

In the case of the linear polarization method, in order to view a linearly polarized image using a linear polarization filter as a good stereoscopic image,
It is necessary to match the polarization angle of the polarizing glasses with the polarizing filter attached to each image light source. Therefore, when the head wearing the polarized glasses is tilted or when the image composition plane is viewed from a direction shifted from the center of the screen, the angle of polarization is shifted from the optimum polarization angle. become unable.

On the other hand, in the case of the circularly polarized light system, since the circularly polarized light is used, there is no deviation in the polarization angle, and the image can be viewed as a substantially perfect stereoscopic image.

As a conventional projector type stereoscopic video display device, a front projection type projector as shown in FIG. 12 has been put to practical use. The image light source 4 to which the right-eye image 2 of the projector 1 is supplied and the image light source 5 to which the left-eye image 3 is supplied (including R, G, and B image light transmission units) are circles having different polarization directions. Polarizing filters 6 and 7 are respectively attached. That is, a clockwise circular polarization filter 6 is attached to the image light source 4, and a counterclockwise circular polarization filter 7 is attached to the image light source 5. The image light 8 derived from the image light source 4 is clockwise circularly polarized light, and the image light 9 derived from the image light source 5 is counterclockwise circularly polarized light. Two sets of image light 8, 9
Are synthesized and reflected by the reflective screen 10 which is an image synthesis surface. Here, due to the reflection, the image light 8 changes from clockwise circular polarization to counterclockwise circular polarization, and the image light 9 changes from counterclockwise circular polarization to clockwise circular polarization. The circularly polarized glasses 11 include clockwise circularly polarized filters 12 for the left and right eyes, respectively.
And the counterclockwise circularly polarizing filter 13 are attached, and the combined image light 8 and image light 9 can be separated and viewed.

The reflection type screen 10 is a metal surface mirror made of aluminum or the like, and does not generate a birefringence phase difference, so that the polarization does not change. Can be seen. Therefore, in the case of a front projection type projector, a circular polarization method which is not affected by the deviation of the polarization angle is optimal.

[Problems to be solved by the invention]

However, when trying to put a stereoscopic image display device into practical use with a rear projection type projector, it is necessary to provide a mirror between the image light source and the image synthesizing surface, or a mirror or transmission screen that is an optical element including the image synthesizing surface. The prior art has not considered that refraction may occur and change the polarization, making it impossible to view a good stereoscopic image.

FIG. 13 shows an example of a rear projection type projector, which is different from the front projection type projector shown in FIG.
A transmissive screen 14 is used in place of the reflective screen 10, and a mirror 15 for bending the optical path to make the optical system compact is added. The two image lights 8 and 9 are reflected by the mirror 15 and are a transmission type screen which is an image synthesis surface.
Synthesized at 14. Here, the image light 8 changes from clockwise circularly polarized light to counterclockwise circularly polarized light due to reflection by the mirror 15, and
The image light 9 changes from left-handed circularly polarized light to right-handed circularly polarized light. Others are the same as FIG.

In a general rear projection type projector that does not display a stereoscopic image, the influence of birefringence on optical performance is not a particular problem. Therefore, the substrate of the transmission screen 14 is formed of a birefringent resin material such as polycarbonate. Further, since the substrate is an extruded plate manufactured by extrusion molding which is excellent in mass productivity, birefringence is larger than that of a cast plate. Further, since the surfaces of the lenticular lens 16 and the Fresnel lens 17 constituting the transmission screen 14 are processed into a lens shape or a prism shape, birefringence occurs due to stress distortion remaining after the processing. further,
Even the mirror 15 whose surface is coated with a protective film, a reflection-enhancing film, or the like generates birefringence. As described above, the rear projection type projector is provided with an optical element having a birefringent phase difference, such as the mirror 15, the lenticular lens 16, and the Fresnel lens 17, between the image light source and the image synthesizing surface.

When circularly polarized light is made incident on an optical element having birefringence as in the conventional apparatus, the image lights 8 and 9 emitted therefrom are changed from circularly polarized light to elliptically polarized light. You cannot see the video.

FIG. 14 shows a case where linearly polarized light of + 45 ° / −45 ° is incident instead of circularly polarized light. That is, a + 45 ° linear polarization filter 18 is attached to the image light source 4, and a −45 ° linear polarization filter 19 is attached to the image light source 5. The video light 20 derived from the video light source 4 is linearly polarized at + 45 °, and the video light 21 derived from the video light source 5 is linearly polarized at −45 °. The two image lights 20, 21 are reflected by the mirror 15,
The images are synthesized on the transmission screen 14 which is the image synthesis surface. Here, due to the reflection at the mirror 15, the image light 20 becomes -45 ° linearly polarized light, and the image light 21 becomes + 45 ° linearly polarized light. The linear polarizing glasses 22 have a + 45 ° linear polarizing filter 23 and a −45 ° linear polarizing filter 24 attached to the left eye and the right eye, respectively, and separate the combined image light 20 and image light 21. Can be viewed. However, except when the optical principal axis of the optical element having a birefringent phase difference is parallel or perpendicular to the polarization direction of the image light source, the image light 20, 21 which emits the same
Respectively change from linearly polarized light to elliptically polarized light, and it becomes impossible to view a good stereoscopic image using the linearly polarized glasses 22. That is, the optical main axis 15a of the mirror 15 is uniformly distributed in a direction perpendicular to the tilt direction of the mirror 15, that is, in a direction parallel to the tilt axis, and is at 45 ° to the polarization direction of the image light sources 4 and 5.
Make Also, the optical main shaft 16a of the lenticular lens 16
Are uniformly distributed in the direction in which the lens-shaped processing surface extends, and form 45 ° with the polarization directions of the image light sources 4 and 5. on the other hand,
The mirror 15 and the lenticular lens 16 have uniform optical principal axes, whereas the Fresnel lens 17 has irregular optical principal directions. That is, since the lens surface of the Fresnel lens 17 is processed concentrically, the optical principal axis 17a of birefringence due to stress distortion remaining after processing is also distributed concentrically and is not uniform. Therefore, there always exists a region where the optical principal axis 17a is not parallel or perpendicular to the polarization direction of the image light sources 4 and 5, and in this region, it is impossible to view a good stereoscopic image.

FIG. 15, FIG. 16, and FIG. 17 are FIGS. 12, 13 respectively.
FIG. 14 shows a state in which a composite image of a single-color right-eye image 2 and a black-only left-eye image 3 is viewed only with the left eye in the apparatus shown in FIG. In a reflective screen, the color becomes black as shown in FIG. 15, whereas in a transmissive screen, it does not become black as shown in FIGS. 16 and 17. Especially,
In the case of circularly polarized light, as shown in FIG.
Leaks into the left eye. Further, in the case of linearly polarized light of + 45 ° / −45 °, only the optical main axis 17a of the Fresnel lens 17 is located in the direction of ± 45 ° from the center of the screen.
Although the leakage is slightly small because it is parallel or perpendicular to the polarization direction of 5, the leakage is large in other regions. As described above, it is not possible to view a good three-dimensional image in an area where the color is not completely black. This problem is not limited to the rear projection type projector. Even in a front projection type projector, a reflective screen 10 in which a birefringent phase difference occurs
A problem arises when is used. Further, even in the cathode ray tube system, there is a problem when a half mirror that generates a birefringent phase difference is used.

SUMMARY OF THE INVENTION An object of the present invention is to provide a good stereoscopic image with no change in polarization even if an optical element provided between an image light source and an image combining surface or an optical element including the image combining surface has a birefringent phase difference. It is an object of the present invention to provide a three-dimensional video display device capable of performing the above-mentioned.

[Means for solving the problem]

In order to achieve the above object, in the present invention, the two image light sources are configured to derive two sets of image light linearly polarized in polarization directions different from each other by 90 °, and between the image light source and the image combining surface. The optical element having a birefringent phase difference provided, or the image combining surface having a birefringent phase difference, the optical principal axis direction of the optical element or the optical principal axis of the image combining surface being uniform with respect to a certain direction. It is configured to be parallel or perpendicular to the polarization direction of the image light source.

In order to configure the optical principal axis of the optical element to be parallel or perpendicular to the polarization direction of the image light source, the tilt direction of the mirror is configured to be parallel or perpendicular to the polarization direction of the image light source.

Also, in order to configure the optical principal axis of the optical element so as to be parallel or perpendicular to the polarization direction of the image light source, a transmission screen in which lens-shaped or prism-shaped processing surfaces extending in one direction are continuously arranged. Is configured so that the direction of extension is parallel or perpendicular to the polarization direction of the image light source.

As described above, in order that the direction of extension of the transmission screen in which the lens-shaped or prism-shaped processing surfaces extending in one direction are continuously arranged is parallel or perpendicular to the polarization direction of the image light source, The transmissive screen includes one or two lenticular lenses whose arrangement directions are different from each other by 90 °.

Alternatively, for the same purpose, the transmission screen includes one or two linear Fresnel lenses whose arrangement directions are different from each other by 90 °.

Next, in the present invention, among the optical elements having the birefringence phase difference, the phase difference of the optical element whose optical principal axis direction is not uniform is larger than the phase difference of the optical element whose optical principal axis direction is uniform. Is also reduced.

In order to configure the phase difference of the optical element whose optical main axis direction is not uniform as described above to be smaller than the phase difference of the optical element whose optical main axis direction is uniform, the transmission type optical element is used. The phase difference of the Fresnel lens forming the screen is configured to be smaller than the phase difference of the lenticular lens.

Then, in order to configure so that the phase difference of the Fresnel lens constituting the transmission screen is smaller than the phase difference of the lenticular lens, the Fresnel lens is manufactured by molding an ultraviolet curable resin, and the Fresnel lens is directly Manufactured by cutting.

Also, in the present invention, a viewer wearing polarized glasses can view a good stereoscopic image even when the head is tilted or when the image combining surface is viewed from a direction shifted from the center of the screen. In order to achieve this, the polarized glasses are circularly polarized glasses with different circular polarization directions, and the optical axis of birefringence between the image combining surface and the polarized glasses is at 45 ° to the polarization direction of the image light source.
The configuration is such that a quarter-wave plate is provided.

[Action]

According to the above configuration, even if there is a birefringent phase difference in the optical element, when linearly polarized light parallel or perpendicular to the optical principal axis of the optical element whose optical axis principal axis direction is uniform is incident, the image is emitted therefrom. Since the light remains linearly polarized, it can be viewed as a good stereoscopic image.

In addition, since the optical principal axis of the mirror arranged in a tilted direction is a direction perpendicular to the tilt direction of the mirror, that is, a direction parallel to the tilt axis, the tilt direction of the mirror is parallel or perpendicular to the polarization direction of the image light source. With this configuration, the optical main axis of the mirror can be configured to be parallel or perpendicular to the polarization direction of the image light source, and even if the mirror has a birefringent phase difference, it can be viewed as a good stereoscopic image.

Moreover, since the optical axis of a transmission type screen in which lens-like or prism-like processing surfaces extending in one direction, such as a lenticular lens or a Fresnel lens, are arranged continuously, the processing surface extends in the direction. If the current direction is configured to be parallel or perpendicular to the polarization direction of the image light source,
The optical axis of the transmission screen can be configured so as to be parallel or perpendicular to the polarization direction of the image light source, and even if the transmission screen has a birefringence phase difference, it can be viewed as a good stereoscopic image.

Further, if the transmissive screen is configured to include one or two lenticular lenses whose arrangement directions are different from each other by 90 °, the optical main axis of each lenticular lens is parallel or perpendicular to the polarization direction of the image light source. Even if the lenticular lens has a birefringent phase difference, it can be viewed as a good stereoscopic image.

Alternatively, if the transmissive screen is configured to include one or two linear Fresnel lenses whose arrangement directions are different from each other by 90 °, the optical principal axis of each linear Fresnel lens is parallel or perpendicular to the polarization direction of the image light source. Thus, even if the linear Fresnel lens has a birefringent phase difference, it can be viewed as a good stereoscopic image.

Next, since there is an area that is not parallel or perpendicular to the polarization direction of the image light source in the optical element in which the direction of the optical main axis is not uniform, the phase difference of the optical element in which the direction of the optical main axis is not uniform is If the configuration is such that the phase difference of the optical element in which the direction of the optical main axis is uniform is smaller than that of the optical element, a more excellent stereoscopic image can be viewed.

In a transmission screen having a configuration including a Fresnel lens and a lenticular lens, the Fresnel lens is an optical element in which the direction of the optical principal axis is not uniform, and the lenticular lens is an optical element in which the direction of the optical principal axis is uniform. Therefore, if the phase difference of the Fresnel lens is configured to be smaller than the phase difference of the lenticular lens, a more excellent stereoscopic image can be viewed.

In addition, compared to extrusion molded products such as those used for lenticular lenses, Fresnel lenses are manufactured by molding UV-curable resin because the stress-strain remaining after processing is small and the phase difference is small. Then, the phase difference of the Fresnel lens can be configured to be smaller than the phase difference of the lenticular lens, and a more excellent stereoscopic image can be viewed.

In addition, direct cut products have less stress distortion remaining after processing and less phase difference than extruded products such as lenticular lenses, so if a Fresnel lens is manufactured by direct cutting, the phase difference of the Fresnel lens can be reduced. However, it can be configured to be smaller than the phase difference of the lenticular lens, and can be viewed as a better stereoscopic image.

The polarized glasses are circularly polarized glasses with different circular polarization directions, and a quarter-wave plate is provided between the image combining surface and the polarized glasses so that the optical principal axis of birefringence forms 45 ° with the polarization direction of the image light source. With this configuration, it is possible to make the polarized light between the image combining surface and the polarizing glasses in which no optical element having birefringence is provided, so that the viewer wearing the polarizing glasses tilts the head or the image. Even when the composite surface is viewed from a direction shifted from the center of the screen, a good stereoscopic image can be viewed.

〔Example〕

 Hereinafter, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 shows an embodiment of a rear projection type projector which is a stereoscopic image display device according to the present invention.
Compared with the conventional rear projection type projector shown in the figure, the image light sources 4 and 5 are replaced with conventional clockwise / counterclockwise circularly polarizing filters 6 and 7 and + 45 ° / −45 ° linear polarizing filters 18 and 19. In addition, horizontal / vertical linear polarization filters 25 and 26 are used.

That is, a vertical linear polarization filter 25 is attached to the image light source 4, and a horizontal linear polarization filter 26 is attached to the image light source 5. The image light 27 derived from the image light source 4 is vertically linearly polarized light, and the image light 28 derived from the image light source 5 is horizontally linearly polarized light. The two sets of image light 27 and 28 are reflected by the mirror 15 and are synthesized by the transmission screen 14 which is an image synthesis surface. Here, since the polarization direction is horizontal / vertical, the image light 27 remains vertically linearly polarized light and the image light 28 remains horizontally linearly polarized even by reflection by the mirror 15. The linearly polarized glasses 29 are provided with a horizontal linearly polarized light filter 30 and a vertical linearly polarized light filter 31 for the left eye and the right eye, respectively, so that the synthesized image light 27 and the image light 28 can be separated and viewed. Can be.

Here, the optical main axis 15a of the mirror 15 is horizontal,
It is parallel or perpendicular to the polarization directions of the image light sources 4 and 5. The optical main axis 16a of the lenticular lens 16 is in the vertical direction, and is parallel or perpendicular to the polarization directions of the image light sources 4 and 5. Since the optical principal axis 17a of the Fresnel lens 17 is concentrically distributed, a region where the optical principal axis 17a is parallel or perpendicular to the polarization direction of the image light sources 4 and 5 exists in the horizontal or vertical direction from the center of the screen. I do.

FIG. 2 shows a state in which the composite image of the right-eye image 2 of only white and the left-eye image 3 of only black is viewed only with the left eye in the apparatus shown in FIG. FIG. 2 using horizontal / vertical linear polarization filters 25 and 26 is shown in FIG. 16 using clockwise / counterclockwise circular polarization filters 6 and 7, or + 45 ° / −45 °.
Compared to FIG. 17 using linear polarization filters 18 and 19,
Leakage is small. However, in an area in the ± 45 ° direction from the center of the screen, only the optical main axis 17a of the Fresnel lens 17 forms ± 45 ° with the polarization direction of the image light sources 4 and 5, so that leakage is slightly large, but in other areas, Leakage is small. As described above, since most of the screen is solid black, a good stereoscopic image can be viewed.

In the apparatus shown in FIG. 1, if the birefringence of the Fresnel lens 17 is made sufficiently smaller than the birefringence of the lenticular lens 16, the entire screen becomes black and the direction of the main optical axis is parallel or parallel to the polarization direction of the image light source. Even in an area that is not a right angle, a better stereoscopic image can be viewed.

To obtain the above relationship, for example, a lenticular lens
16 is manufactured by extrusion molding which has a large birefringence but is excellent in mass productivity, while a Fresnel lens 17 is a photo-polymerization called a 2p method using an ultraviolet curable resin for a cast substrate having a small birefringence. ) Method. Alternatively, the Fresnel lens 17 may be manufactured by directly cutting a cast substrate having a small birefringence.

Note that the above relationship is not limited to the Fresnel lens 17 and the lenticular lens 16. That is, the birefringence phase difference of an optical element whose optical main axis direction is not uniform like the Fresnel lens 17 is larger than the birefringence phase difference of an optical element whose optical main axis direction is uniform like the lenticular lens 16. The same effect can be obtained if the configuration is also made smaller.

In the embodiment shown in FIG. 1, the transmission type screen is used.
Although the configuration 14 is constituted by the lenticular lens 16 and the Fresnel lens 17, it is not limited to this.

FIG. 3 shows another embodiment of a rear projection type projector which is a stereoscopic image display device according to the present invention, which is different from the rear projection type projector shown in FIG. 1 in that a lenticular lens 16 and a Fresnel lens 17 are used. Transmission screen
Instead of 14, a transmissive screen 33 constituted by two lenticular lenses 16 and 32 whose arrangement directions are different from each other by 90 °.
Is used. In the present embodiment, except for the Fresnel lens 17 in which the optical principal axis 17a is concentrically distributed, instead, the optical principal axis 17a is parallel or perpendicular to the polarization direction of the image light sources 4, 5.
Since the lenticular lens 32 whose optical axis 32a is horizontal is provided, the optical axes 15a, 16a and 32a are all parallel or perpendicular to the polarization directions of the image light sources 4 and 5.

FIG. 4 shows a state in which the composite image of the right-eye image 2 of only white and the left-eye image 3 of black is viewed only with the left eye in the apparatus shown in FIG. Two lenticular lenses
FIG. 4 using a transmission type screen 33 constituted by 16 and 32 has less leakage than FIG. 2 using a transmission type screen 14 constituted by a lenticular lens 16 and a Fresnel lens 17. Since the entire screen is solid black as in FIG. 15 in the case of the projection type projector, a good stereoscopic image can be seen.

FIG. 5 shows still another embodiment of a rear projection type projector which is a stereoscopic image display device of the present invention.
Compared with the rear projection type projector shown in the figure, instead of the transmissive screen 14 having the lenticular lens 16 and the Fresnel lens 17, two linear Fresnel lenses 34, 35 whose orientation directions differ from the lenticular lens 16 by 90 ° are different from each other.
A transmission screen 36 having the following configuration is used. In this embodiment, except for the Fresnel lens 17 in which the optical principal axes 17a are concentrically distributed, the optical principal axes 34a and 35a are respectively horizontal so as to be parallel or perpendicular to the polarization directions of the image light sources 4 and 5 instead. / Vertical linear Fresnel lens 3
Since the optical axes 4 and 35 are provided, the optical principal axes 15a, 16a, 34a and 35a are all parallel or perpendicular to the polarization directions of the image light sources 4 and 5. Furthermore, the two linear Fresnel lenses 34 and 35
It has the same light converging function as the Fresnel lens 17.
Therefore, while being able to see good stereoscopic images,
Due to the light convergence action, the brightness around the screen is improved as compared with the apparatus shown in FIG. 3, and the same brightness as the apparatus shown in FIG. 1 can be obtained.

In the embodiment shown in FIGS. 1, 3 and 5, horizontal / vertical linear polarizing glasses 29 are used corresponding to the horizontal / vertical linear polarizing filters 25 and 26 attached to the image light sources 4 and 5, respectively. But it is not limited to this. An example is shown below.

FIG. 6 shows still another embodiment of a rear projection type projector which is a stereoscopic image display device of the present invention.
Compared to the rear projection type projector shown in the figure, circularly polarized glasses 11 are used in place of the linearly polarized glasses 29, and a birefringent optical principal axis 37a is provided between the transmission type screen 36 and the circularly polarized glasses 11 by the image light source 4. 1/4 of 45 ° with 5 polarization directions
This is a configuration in which a wave plate 37 is added. In the present embodiment, even if the space between the transmission type screen 36 and the circularly polarized glasses 11 is circularly polarized, the circularly polarized light does not change to elliptically polarized light because no optical element having birefringence is provided here. . In addition, since the light is circularly polarized, even if the viewer wearing the circularly polarized glasses 11 tilts his head or sees the transmissive screen 36 from a direction shifted from the center of the screen, the deviation of the polarization angle is not a problem. You can see good stereoscopic images.

Note that, as described above, a good stereoscopic image can be viewed even when the viewer wearing polarized glasses tilts his / her head or views the image synthesis surface from a direction shifted from the center of the screen. The present invention is not limited to circularly polarized glasses, but is also possible with linearly polarized glasses. An example is shown below.

FIG. 7 is a perspective view of an embodiment of the linearly polarized glasses 29 used in the stereoscopic image display device of the present invention, and FIG. 8 is a sectional view of a main part thereof. In the figure,
The horizontal / vertical linearly polarizing filters 30 and 31 are configured to be rotatable while floating in water 39 filled in the space of the glasses frame 38. In addition, the horizontal / vertical linear polarizing filters 30 and 31 have a lift 40 at the top and a weight at the bottom.
41 are provided, and operate so as to always have the same angle using gravity or buoyancy. As shown in FIG. 9, even if the glasses frame 38 is rotated with respect to the stereoscopic image display device by tilting the head, the horizontal / vertical linear polarization filters 30 and 31 of the linear polarization glasses 29 deviate from the optimum polarization angle. Because there is no such thing, a good stereoscopic image can be seen.

The three-dimensional image display device is mainly used for displaying a three-dimensional image as described above, but is not limited to this. An example is shown below.

FIG. 10 shows an embodiment of a rear projection type projector which is an image display device provided for uses other than the stereoscopic image display of the present invention, and differs from the rear projection type projector shown in FIG. Instead of the circularly polarized glasses 11 having the same polarization direction, circularly polarized glasses 42 and 43 having the same left and right polarization directions are used.
In addition, corresponding to each circularly polarized glasses 42, 43, earphone 44,
Attach 45. Then, a first video 47 and a first audio 48 are supplied from the first video / audio source 46 to the video light source 4 and the earphone 44, respectively, and a second video 50 is supplied to the video light source 5 and the earphone 45 from the second video / audio source 49, respectively. The second audio 51 is supplied. In the present embodiment, a function is provided to separate and view only one of the two sets of images 47 and 50 and to independently listen to the sounds 48 and 51 corresponding to the two sets of images 47 and 50, respectively. Therefore, a plurality of persons can simultaneously watch two separate videos and sounds using one video display device.

According to the present apparatus, since two image light sources 4 and 5 are provided, a normal single image can be displayed, or two images can be displayed in a superimposed manner and viewed by removing polarized glasses. , Superimpose function can be realized. Since the conventional superimpose function was realized by electrically synthesizing video signals, it was necessary to synchronize two video signals. However, the superimpose function of the present invention synthesizes video light. It is realized by
There is no need to synchronize the two video signals. In addition, in the conventional superimpose function, a plurality of persons can all see only the same image, but the superimpose function of the present invention is such that only a person wearing one of the polarizing glasses 42 and 43 has two persons. Only one of the images 47 and 50 can be viewed separately. For example, if a movie without superimposed subtitles is supplied to the first video 47 and a superimposed subtitle is supplied to the second video 50, a person who does not wear the polarized glasses 42 can watch a movie with superimposed subtitles. Only those who wear the can watch movies without subtitles.

In the embodiment shown in FIG. 10, the circularly polarized glasses 42,
43 was used, but is not limited to this. For example, a circularly polarized contact lens may be used instead of the circularly polarized glasses. The contact lens rotates in the eye, but there is no problem in the deviation of the polarization angle because it is circularly polarized light. Further, as shown in FIG. 11, circularly polarized light comprising a circularly polarized light filter 52,
53 may be used. In this case, there is no need to wear glasses or contact lenses.

〔The invention's effect〕

According to the present invention, in a binocular stereoscopic image display device,
Even if an optical element (mirror, transmissive screen, etc.) provided between the image light source and the image synthesizing surface or including the image synthesizing surface has a birefringent phase difference, a viewer can obtain a good stereoscopic image. You can see. As a result, even for a rear-projection type projector which has conventionally had these problems, it is possible to express a projector capable of viewing a good stereoscopic image.

In addition, the polarized glasses used in the stereoscopic image display device of the present invention can always maintain the polarizing filter of the polarized glasses at an optimum polarization angle, so that the viewer tilts his / her head, Even when viewing from a more shifted direction, it is possible to always see a good stereoscopic video.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an embodiment of a stereoscopic video display apparatus according to the present invention, FIG. 2 is a front view of a transmission screen for explaining the effect of the embodiment, and FIG. FIG. 4 is a perspective view showing another embodiment of the video display device, FIG. 4 is a front view of the transmission screen for explaining the effect of the embodiment,
5 and 6 are perspective views showing still another embodiment of the three-dimensional image display device of the present invention, and FIG. 7 is a perspective view showing one embodiment of linearly polarized glasses used for the three-dimensional image display device of the present invention. FIG. 8, FIG. 8 and FIG. 9 are a sectional view and a front view, respectively, of an essential part of the linearly polarized glasses, FIG. 10 and FIG. 11 are perspective views showing an embodiment of the image display device of the present invention, FIG. , FIG. 13 and FIG. 14 are perspective views each showing an example of a conventional stereoscopic video display device, FIG. 15, FIG. 16 and FIG. 17 are screens in FIG. 12, FIG. 13 and FIG. FIG. DESCRIPTION OF SYMBOLS 1 ... Projector, 2 ... Right-eye image 3 ... Left-eye image 4, 5 ... Image light source 11 ... Circularly polarized glasses, 14 ... Transmissive screen 15 ... Mirror, 15a ... Optical Main axis 16 Lenticular lens 16a Optical main axis 17 Fresnel lens 17a Optical main axis 25 Vertical linear polarization filter 26 Horizontal linear polarization filter 27 28 Image light 29 Linear polarization Glasses 30… Horizontal linear polarization filter 31… Vertical linear polarization filter 32… Lenticular lens, 32 a… Optical spindle 33… Transmissive screen 34… Linear Fresnel lens, 34 a… Optical spindle 35… Linear Fresnel lens , 35a Optical main axis 36 Transmission screen 37 Quarter-wave plate 38 Glass frame 39 Water 40 Water weight 42, 43 Circularly polarized glasses 44 45 ... earphone, 46 ... first video and audio source 47 ... First image, 48 ...... first audio 49 ...... second video audio source, 50 ...... second image 51 ...... second voice, 52 and 53 ...... circularly polarized light partition

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Masaki Yoshii 292 Yoshida-cho, Totsuka-ku, Yokohama-shi, Kanagawa Prefecture Inside the Hitachi, Ltd.Production Technology Research Laboratory (72) Inventor Yasuo Amano 292 Yoshida-cho, Totsuka-ku, Yokohama-shi, Kanagawa Stock (56) References JP-A-50-45655 (JP, A) JP-A-63-10979 (JP, A) Full-scale 1987-120 (JP, U) Full-scale 1988- 150918 (JP, U) Fully open 60-110823 (JP, U)

Claims (8)

(57) [Claims] 1. An optical system, comprising: two sets of image light sources for deriving two sets of image light that can be viewed on top of each other; and a birefringent phase difference provided between the image light source and the image synthesizing surface. A stereoscopic image that has a mirror whose tilting direction is the same as the direction of the main axis and that can be viewed by combining two sets of image light through polarized glasses with different left and right polarization directions. In the display device, the two sets of image light sources derive two sets of image light linearly polarized in polarization directions different from each other by 90 °, and the optical axis of the mirror in which the direction of the optical main axis is uniform with respect to the tilt direction. A stereoscopic image display device, wherein the main axis is configured to be parallel or perpendicular to the polarization direction of the image light source. 2. An optical system, comprising: two sets of image light sources for deriving two sets of image light that can be viewed by being superimposed on each other; and a birefringent phase difference provided between the image light source and the image combining surface. A transmission type screen in which the direction of the main axis is uniform with respect to the direction in which the lens-shaped or prism-shaped processing surfaces extending in one direction are continuously arranged, In a stereoscopic image display device capable of viewing a stereoscopic image by combining a set of image lights, two sets of image light sources derive two sets of image lights linearly polarized in polarization directions different from each other by 90 °. The direction of
The optical principal axis of the transmission screen, which is uniform with respect to the direction in which the lens-shaped or prism-shaped processing surfaces extending in one direction are continuously arranged, is parallel or perpendicular to the polarization direction of the image light source. A stereoscopic video display device characterized by comprising. 3. A three-dimensional image display apparatus according to claim 2, wherein the transmission screen includes one or two lenticular lenses whose arrangement directions are different from each other by 90 °. Display device. 4. A three-dimensional image display device according to claim 2, wherein the transmission type screen includes one or two linear Fresnel lenses whose arrangement directions are different from each other by 90 °. Video display device. 5. An optical system, comprising: two sets of image light sources for deriving two sets of image light that can be viewed by being superimposed on each other; and a birefringent phase difference provided between the image light source and the image synthesizing surface. A lenticular lens in which the direction of the principal axis is uniform with respect to a direction in which a lens-shaped processing surface extending in one direction is continuously arranged, and there is a phase difference of birefringence, and the direction of the optical principal axis is not uniform A transmission type screen having a configuration including a Fresnel lens, and a stereoscopic image display device capable of viewing a stereoscopic image by combining two sets of image light through polarized glasses of different left and right polarization directions. A stereoscopic image characterized by deriving two sets of image light linearly polarized in 90 ° different polarization directions, wherein the phase difference of the Fresnel lens is smaller than the phase difference of the lenticular lens. Display device. 6. The three-dimensional image display device according to claim 5, wherein the Fresnel lens is manufactured by molding an ultraviolet curable resin. 7. The three-dimensional image display device according to claim 5, wherein the Fresnel lens is manufactured by direct cutting. 8. The stereoscopic image display device according to claim 1, wherein the polarized glasses are circularly polarized glasses having different circularly polarized light directions on the left and right, and a plurality of polarized glasses are provided between the image combining surface and the polarized glasses. The main optical axis of refraction is 45 ° with the polarization direction of the image light source
A three-dimensional image display device provided with a quarter-wave plate.